reserve e,u for set;
reserve X, Y for non empty TopSpace;

theorem Th2:
  for A being continuous Function of X,Y, G being Subset of Y
  holds A"Int G c= Int(A"G)
proof
  let A be continuous Function of X,Y, G be Subset of Y;
  let e be object;
A1: A"Int G c= A"G by RELAT_1:143,TOPS_1:16;
  [#]Y <> {};
  then
A2: A"Int G is open by TOPS_2:43;
  assume e in A"Int G;
  hence thesis by A2,A1,TOPS_1:22;
end;
